Lennox Furnace Code E241
Safety fault
Flame sensed out of sequence. The control still sees flame at a point in the cycle when there should be none, which suggests gas is still burning after the valve was told to close.
Manual wording: “Flame sensed out of sequence - Flame still present. Shut off gas. Check for gas valve leak. Replace, if necessary.”
Documented for: EL296UHE and SLP98UHV series
Likely causes, most common first
- Gas valve leaking through and letting gas continue to burn
- Flame sense circuit reading a false signal
What you can safely check yourself
- Turn the furnace power switch off at the switch beside the furnace
When to call a technician
The manual's action is to shut off the gas and check the gas valve for a leak, replacing it if necessary. Turn the furnace off and call a technician right away. If you smell gas, leave the house and call the gas utility from outside.
A Lennox furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- EL296UHE Service Literature (Corp. 1246-L10), Table 4 - Integrated Control Diagnostic Codes (Lennox Industries Inc., EL296UHE series 96% AFUE two-stage upflow/horizontal gas furnace (EL296UH045XE36B, EL296UH070XE36B, EL296UH090XE48C)) · checked 2026-08-25
- SLP98UHV Service Literature (Corp. 1029-L7), Table 14 - LED 7 Segment Status / Error Code and Integrated Control Diagnostic Codes (Lennox Industries Inc., SLP98UHV series variable-capacity communicating gas furnace (66,000-132,000 Btuh)) · checked 2026-08-25